British biochemist Edward Charles Dodds studied endocrinology, and in 1938 discovered a synthetic compound that mimicked estroene, rarest of the three naturally occurring estrogens (female sex hormones). Dodds did not patent the compound, diethylstilbestrol, which allowed its economical mass production for numerous medicinal purposes including menopausal symptoms, suppression of postpartum lactation, general estrogen deficiency, and to prevent miscarriages among pregnant women. Over subsequent decades the drug's toxic and carcinogenic effects became known, including its ability to trigger genetic changes passed from mothers to their children.